Halozyme Therapeutics and ViroPharma Announce $83 Million Global Licensing Agreement to Develop Subcutaneous Cinryze® (C1 esterase inhibitor [human])

SAN DIEGO, May 11, 2011 /PRNewswire/ -- Halozyme Therapeutics, Inc. (Nasdaq: HALO) and ViroPharma Incorporated (Nasdaq: VPHM), today announced the signing of a worldwide exclusive licensing agreement for the use of rHuPH20 (recombinant human hyaluronidase) in the development of a subcutaneous formulation of Cinryze (C1 esterase inhibitor [human]). Under terms of the agreement, Halozyme may receive up to $83 million, commencing with an upfront payment of $9 million and total potential future milestone payments of $74 million dependent upon the achievement of clinical and regulatory targets, plus a 10% royalty on future sales of the combination of Cinryze with rHuPH20. The license provides ViroPharma with exclusivity to C1 esterase inhibition and to the hereditary angioedema (HAE) indication, along with three additional orphan indications. ViroPharma will fund all development and commercialization expenses for the program. Additional terms of the transaction have not been disclosed.

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Cinryze has received FDA approval for intravenous administration for routine prophylaxis against angioedema attacks in adolescent and adult patients with hereditary angioedema. A combination formulation of Cinryze with rHuPH20 for subcutaneous, or under the skin, administration is expected to enter clinical trials by the end of the year. The initial focus of the collaboration will be on the development of a novel subcutaneous formulation of Cinryze for routine prophylaxis against attacks of HAE.

"Halozyme's rHuPH20 enzyme may facilitate the subcutaneous administration and absorption of a broad range of pharmaceuticals and biologics, including plasma-derived proteins such as Cinryze," stated Gregory I. Frost, Ph.D., Halozyme's president and CEO. "The commercial success of Cinryze is notable, and we look forward to working with ViroPharma to simplify the self-administration of this important biologic that may ultimately provide a more convenient product for as many people as possible with HAE worldwide."

"This collaboration is consistent with our goals of continually providing innovative product enhancements, advancing long term solutions to meet the needs of our patients, and helping to maintain and build Cinryze brand loyalty for years to come," commented Colin Broom, M.D., ViroPharma's chief scientific officer. "The goal of our broad subcutaneous Cinryze program is to enable more patients with hereditary angioedema to benefit from access to convenient formulations of Cinryze to prevent their HAE attacks."

About Cinryze (C1 esterase inhibitor [human])

Cinryze is a highly purified, pasteurized and nanofiltered plasma-derived C1 esterase inhibitor product that has been approved by U.S. FDA for routine prophylaxis against angioedema attacks in adolescent and adult patients with HAE. C1 inhibitor therapy has been used acutely for more than 35 years in Europe to treat patients with C1 inhibitor deficiency.

Severe hypersensitivity reactions to Cinryze may occur. Thrombotic events have occurred in patients receiving Cinryze for routine prophylaxis, and in patients receiving off-label high dose C1 inhibitor therapy. Monitor patients with known risk factors for thrombotic events.  With any blood or plasma derived product, there may be a risk of transmission of infectious agents, e.g. viruses and, theoretically, the CJD agent. The risk has been reduced by screening donors for prior exposure to certain virus infections and by manufacturing steps to reduce the risk of viral transmission including pasteurization and nanofiltration. The most common adverse reactions observed have been upper respiratory infection, sinusitis, rash and headache. No drug-related serious adverse events (SAEs) have been observed in clinical trials.

Cinryze is currently approved in the U.S. for intravenous use only. A dose of 1000 Units of Cinryze can be administered every 3 or 4 days for routine prophylaxis against angioedema attacks in HAE patients. Cinryze is administered at an injection rate of 1 mL per minute.

About Hereditary Angioedema (HAE)

HAE is a rare, severely debilitating, life-threatening genetic disorder caused by a deficiency of C1 inhibitor, a human plasma protein. This condition is the result of a defect in the gene controlling the synthesis of C1 inhibitor. C1 inhibitor maintains the natural regulation of the contact, complement, and fibrinolytic systems, that when left unregulated, can initiate or perpetuate an attack by consuming the already low levels of endogenous C1 inhibitor in HAE patients. Patients with C1 inhibitor deficiency experience recurrent, unpredictable, debilitating, and potentially life threatening attacks of inflammation affecting the larynx, abdomen, face, extremities and urogenital tract. Patients with HAE experience approximately 20 to 100 days of incapacitation per year. There are estimated to be at least 6,500 people with HAE in the United States.

For more information on HAE, visit the U.S. HAE Association's website at: www.haea.org or the HAEi (International Patient Organization for C1 Inhibitor Deficiencies) at www.haei.org.

About Halozyme

Halozyme Therapeutics is a biopharmaceutical company developing and commercializing products targeting the extracellular matrix for the insulin, cancer, dermatology and drug delivery markets. The company's product portfolio is based primarily on intellectual property covering the family of human enzymes known as hyaluronidases and additional enzymes that affect the extracellular matrix. Halozyme's Enhanze™ technology is a novel drug delivery platform designed to increase the absorption and dispersion of biologics. The company has key partnerships with Roche, Baxter and ViroPharma to apply Enhanze technology to therapeutic biologics including Herceptin®, MabThera®, immunoglobulin and Cinryze®. Halozyme's Ultrafast Insulin program combines its rHuPH20 enzyme with mealtime insulins, which may produce more rapid absorption, faster action, and improved glycemic control. The product candidates in Halozyme's pipeline target multiple areas of significant unmet medical need. For more information visit www.halozyme.com.

About ViroPharma Incorporated

ViroPharma Incorporated is an international biopharmaceutical company committed to developing and commercializing innovative products for physician specialists to enable the support of patients with serious diseases for which there is an unmet medical need, and providing rewarding careers to employees. ViroPharma commercializes Cinryze® (C1 esterase inhibitor [human]) for routine prophylaxis against angioedema attacks in adolescent and adult patients with hereditary angioedema (HAE). ViroPharma commercializes Vancocin®, approved for oral administration for treatment of antibiotic-associated pseudomembranous colitis caused by Clostridium difficile and enterocolitis caused by Staphylococcus aureus, including methicillin-resistant strains (for prescribing information on ViroPharma's commercial products, please download the package inserts at http://www.viropharma.com/Products.aspx). ViroPharma currently focuses its drug development activities in diseases including C1 esterase inhibitor deficiency and C. difficile infection. ViroPharma routinely posts information, including press releases, which may be important to investors in the investor relations and media sections of its company Web site, www.viropharma.com.

Safe Harbor Statement

In addition to historical information, the statements set forth above include forward-looking statements (including, without limitation, statements concerning the timing and scope of our expected activities under the Halozyme-ViroPharma collaborative partnership) that involve risk and uncertainties that could cause actual results to differ materially from those in the forward-looking statements. The forward-looking statements are also identified through use of the words "believe," "enable," "may," "will," "could," "intends," "estimate," "anticipate," "plan," "predict," "probable," "potential," "possible," "should," "continue," and other words of similar meaning. Actual results could differ materially from the expectations contained in forward-looking statements as a result of several factors, including regulatory approval requirements and competitive conditions. These and other factors that may result in differences are discussed in greater detail in the company's reports on Forms 10-K, 10-Q, and other filings with the Securities and Exchange Commission.

Halozyme Contact
Robert H. Uhl
Senior Director, Investor Relations
(858) 704-8264
[email protected]

SOURCE Halozyme Therapeutics, Inc.